Kinetic energy harvesting methods and apparatus

ABSTRACT

A system, method, and apparatus for kinetic energy harvesting are disclosed. An example kinetic energy harvesting apparatus includes a tubular-shaped magnet housing, a first end-cap magnet configured to connect to a first end of the magnet housing and a second end-cap magnet configured to connect to a second end of the magnet housing. The apparatus also includes a first wire coil configured to be connected to the magnet housing between the first end and a center of the magnet housing and a second wire coil configured to be connected to the magnet housing between the second end and the center of the magnet housing. The apparatus further includes a central magnet configured to be located within the magnet housing between the first end and the second end such that the central magnet is suspended within the magnet housing.

PRIORITY CLAIM

The present application claims priority to and the benefit of U.S.Provisional Patent Application No. 61/932,417 filed on Jan. 28, 2014,U.S. Provisional Patent Application No. 62/001,634 filed on May 22,2014, and U.S. Provisional Patent Application No. 62/056,770 filed onSep. 29, 2014, the entirety of which are incorporated herein byreference.

BACKGROUND

Once considered a novelty or luxury, portable electronic devices havebecome prevalent throughout society. Billions of people own portableelectronic devices including cellphones, smartphones, tablet computers,laptops, personal digital assistants, personal health meters, personalmusic players, or wearable cameras. As technology advances, the numberand types of portable electronic devices is expected to increasesignificantly. For instance, smart eyewear and smartwatches are on theverge of becoming mainstream. One common thread among these devices isthat they all operate on a battery that provides sufficient powerranging from a few hours to a few days.

Kinetic energy harvesting devices have been developed to provide aremote or portable source of energy for the billions of portableelectronic devices. The goal of these energy harvesting devices is toextend the battery life of the portable devices when a user does nothave ready access to an electrical outlet. Advertisements show kineticenergy harvesting devices being used on camping trips, travel to exoticlocations, emergency situations, business meetings, and in acar/airplane. However, known kinetic energy harvesting devices have notbecome widely adopted because these devices are generally inefficient,ineffective, and/or cumbersome.

Generally, known kinetic energy harvesting devices use rotatorygenerators, thermoelectric technologies, or photovoltaic technologies tocharge a battery or a portable device directly. However, each devicerequires a specific kinetic activity to adequately capture energy. Forinstance, some rotatory-based devices require a user to shake or make aswirling motion with their hand. Other energy harvesting devices arerequired to be strapped onto a user's shoe or worn on their wrist, whichis oftentimes uncomfortable. These devices may adequately capture energywhile a user is making the intended motion. However, users oftentimesbecome weary of making the same motion long enough for the device tocapture enough energy. Really, how long is a user expected to rapidlyshake their hand in public to supposedly charge a device!

Other energy harvesting devices such as thermoelectric and photovoltaicdevices are configured to passively capture energy from heat, light,etc. While these devices are adequate for charging a wristwatch (not asmartwatch), these devices are not adequate or efficient enough tocapture sufficient energy to charge a portable electronic device. Somemanufacturers have attempted to improve energy harvesting by increasingthe size of the energy harvesting actuator/transducer. However, theincreased size reduces the portability and comfort of using/wearingthese energy harvesting devices.

SUMMARY

The present disclosure provides a new and innovative system, method, andapparatus for harvesting kinetic energy. The system, method, andapparatus use at least one central magnet that is suspended within atubular-shaped housing. The central magnet is configured to move throughat least one inductor coil, thereby mirroring movement of a user. Themovement of the magnet through the inductor coil generates a voltageused to charge a battery. A user may connect the battery to a portableelectronic device (e.g., a smartphone) to accordingly charge theportable electronic device. The movement and/or oscillation of thecentral magnet may be regulated or controlled by adjustable (ordetachable) end-cap magnets, which are placed on either side of thehousing.

In an example embodiment, a kinetic energy harvesting apparatus includesa magnet housing configured to have a tubular shape, a first end-capmagnet configured to connect to a first end of the magnet housing, and asecond end-cap magnet configured to connect to a second end of themagnet housing. The example apparatus also includes a first wire coilconfigured to be connected to the magnet housing between the first endand a center of the magnet housing and a second wire coil configured tobe connected to the magnet housing between the second end and the centerof the magnet housing. The apparatus further includes a central magnetconfigured to be located within the magnet housing between the first endand the second end such that a north-pole of the central magnet faces anorth-pole of the first end-cap magnet and a south-pole of the centralmagnet faces a south-pole of the second end-cap magnet. Thisconfiguration causes the central magnet to be suspended between thefirst and second end-caps of the magnet housing.

Additional features and advantages of the disclosed system, method, andapparatus are described in, and will be apparent from, the followingDetailed Description and the Figures.

BRIEF DESCRIPTION OF THE FIGURES

FIG. 1 shows a diagram of a kinetic energy harvesting device in anenergy harvesting state, according to an example embodiment of thepresent disclosure.

FIG. 2 shows a diagram of the kinetic energy harvesting device of FIG. 1in a charging state, according to an example embodiment of the presentdisclosure.

FIG. 3 shows a diagram of an exploded-view of the example kinetic energyharvesting device of FIGS. 1 and 2, according to an example embodimentof the present disclosure.

FIG. 4 shows a diagram of circuitry of the example kinetic energyharvesting device of FIGS. 1 to 3, according to an example embodiment ofthe present disclosure.

FIG. 5 shows a diagram of a magnet housing of the example kinetic energyharvesting device of FIGS. 1 to 4, according to an example embodiment ofthe present disclosure.

FIGS. 6 and 7 show diagrams of current generation within wire coils as acentral magnet oscillates, according to an example embodiment of thepresent disclosure.

FIGS. 8 and 9 show diagrams of example graphs that show measuredvoltages across an example wire coil during a period of time, accordingto an example embodiment of the present disclosure.

FIG. 10 shows a diagram of magnet housings within the kinetic energyharvesting device of FIGS. 1 to 7, according to an example embodiment ofthe present disclosure.

FIGS. 11 to 14 show diagrams of different configurations of a magnethousing, according to example embodiments of the present disclosure.

FIGS. 15 to 18 show diagrams of different configurations of end-capmagnets and a central magnet, according to example embodiments of thepresent disclosure.

FIG. 19 shows a diagram where an array of relatively small centralmagnets is used within one or more magnet housings, according to exampleembodiments of the present disclosure.

DETAILED DESCRIPTION

The present disclosure relates in general to a method, apparatus, andsystem for kinetic energy harvesting and, in particular, to a method,apparatus, and system uses at least two inductor coils and a centralmagnet to capture kinetic energy. As disclosed herein, an examplekinetic energy harvesting device or apparatus is configured to convertkinetic energy from a user into electrical energy to charge an internalbattery. The kinetic energy harvesting device is configured to beconnected to a portable electronic device so that the battery of thekinetic energy harvesting device charges a battery (or otherwiseprovides power to) the portable electronic device. The example kineticenergy harvesting device may be adjustable (or tunable) so that energyharvesting is optimized based on a user's activity level or personalcharacteristics.

The example kinetic energy harvesting device is operable in two states:an energy harvesting state 100 and a portable electronic device chargingstate 200. FIG. 1 shows a diagram of a kinetic energy harvesting device102 in the energy harvesting state 100, according to an exampleembodiment of the present disclosure. In this state 100 a user 104 wearsor otherwise possesses the kinetic energy harvesting device 102 whileperforming an activity. The activities may include running, walking,climbing, swimming, bicycling, sitting, sleeping, standing, bouncing ina chair, socializing, riding, playing a sport, having sex, etc.

As described in greater detail below, the kinetic energy harvestingdevice 102 includes one or more central magnets configured to move oroscillate based on the movement of the user 104. The central magnets areeach located within a magnet housing that includes one or more inductivecoils. Kinetic energy is harvested from the user's movement by thecentral magnets moving between the coils. The movement of the centralmagnets relative to the coils cause a change in the magnetic fieldexerted on the coils. The change in magnetic field produces an ACvoltage across the coils, which is rectified into a DC voltage used tocharge a battery. The charged battery may be connected to a portableelectronic device 202 to accordingly charge the portable electronicdevice, as shown in FIG. 2. The example kinetic energy harvesting device102 may charge its internal battery at a rate of 0.1 to 50% of batterylife per hour based on the vigorousness of the user's activity.

It should be appreciated that placement of the kinetic energy harvestingdevice 102 on the hip of the user 104 provides relatively more energyharvesting (and is optimal for tracking human motion) because the hiparea moves most significantly perpendicular to Earth's gravity. In otherwords, during the course of an activity, a user's hip moves the most ina height/vertical direction compared to other body parts of the user,which accordingly induces the greatest movement of the central magnetswithin the kinetic energy harvesting device 102. However, it should beappreciated that the kinetic energy harvesting device 102 has a formfactor that enables it to be worn or placed virtually anywhere on auser. For example, the kinetic energy harvesting device 102 may beplaced in a shirt or pants pocket of a user, on a belt of a user,connected to an arm, wrist, neck, chest, hip, leg, or foot of a user,placed within a bag carried by a user, placed on protective gear (e.g.,a helmet, arm pads, knee pads, etc.) or athletic equipment (e.g.,glasses, goggles, boots, shoes, etc.) worn by a user, and/or placed on amoveable object (e.g., a bicycle, skateboard, scooter, motorcycle,automobile, etc.) being ridden by a user. The kinetic energy harvestingdevice 102 may also be attachable to a pet (e.g., on a dog collar).

While reference throughout this disclose is made to use of the energyharvesting device 102 by a user to charge a portable electronic device,it should be appreciated that the kinetic energy harvesting device 102may be used to charge other devices. For example, the example kineticenergy harvesting device 102 may be used to provide power to a hybrid orelectric automobile/truck/bus/boat. The kinetic energy harvesting device102 may also be used in aerospace applications, oceanic applications,medical applications, or any other application where portableself-contained power is desired/needed.

FIG. 2 shows a diagram of the kinetic energy harvesting device 102 inthe portable electronic device charging state 200, according to anexample embodiment of the present disclosure. In this state 200, thekinetic energy harvesting device 102 is electrically coupled to theportable electronic device 202 (e.g., a user device) via a wiredconnection 204. The portable electronic device 202 may include acellphone, a smartphone, a tablet computer, a laptop, a personal digitalassistant, a personal health meter, a personal music player, a wearablecamera, smart-eyewear, a smartwatch, etc. The wired connection 204 mayinclude, for example, a universal serial bus (“USB”) connection, amicro-USB connection, an Apple® Lightning™ connection, a serialconnection, or any other wired connection. While FIG. 2 shows thekinetic energy harvesting device 102 as having the one wired connection204, it should be appreciated that the kinetic energy harvesting device102 may include two or more wired connections 204.

In some embodiments, the kinetic energy harvesting device 102 may beconfigured to wirelessly charge the device 202. For example, the kineticenergy harvesting device 102 and the device 202 may each includeinductors configured to wirelessly couple to facilitate the wirelesstransmission of power. The transmission may be through and/or inconjunction with a near field communication (“NFC”) connection, aradio-frequency identification (“RFID”) connection, etc. It should beappreciated that the use of wireless power charging enables more thanone portable electronic device to be charged at a time.

Returning to FIG. 2, in the state 200 the example kinetic energyharvesting device 102 is configured to provide an electrical charge tothe portable electronic device 202 via the wired connection 204. Theelectrical charge is used to charge a battery on the device 202. Theelectrical charge is typically between 3V and 4.2V but may range from 1Vto 15V. Using, for example, a 1,000 milliampere-hour (“mAh”) battery,the example kinetic energy harvesting device 102 is configured to chargethe device 202 at a rate of 1% of battery life per minute, which issimilar to the rate at which an electrical outlet charges user devices.In an alternative example, the kinetic energy harvesting device 102 mayprovide power to operate the portable electronic device 202.

Example Energy Harvesting Device

FIG. 3 shows a diagram of an exploded-view of the example kinetic energyharvesting device 102 of FIGS. 1 and 2, according to an exampleembodiment of the present disclosure. The example kinetic energyharvesting device 102 includes a device housing 302 configured toenclose at least one magnet housing 304, a battery 306, circuitry 308,and at least one electrical connection interface 310. The illustratedkinetic energy harvesting device 102 has a weight of 140 grams, similarto the weight of many personal electronic devices. It should beappreciated that FIG. 3 shows only one example of the kinetic energyharvesting device 102. In other embodiments, the kinetic energyharvesting device 102 may include additional or fewer magnet housings304, additional batteries, additional connection interfaces, differentdimensions, a different weight, etc.

The example device housing 302 includes a first side 302 a and a secondside 302 b configured to connect together to enclose the components 304to 310. The first side 302 a and the second side 302 b may comprise anytype of plastic, polymer, rubber, carbon-fiber, wood, metal, etc. Forinstance, the first side 302 a and the second side 302 b may compriseacrylonitrile butadiene styrene (“ABS”), nylon, and/or a polycarbonate.In some instances, the device housing 302 may include a combination ofmaterials including, for example, rubber and plastic. The first side 302a and the second side 302 b are connected together to form a water-tightseal. Such a configuration protects the components 304 to 310 fromwater, dust, light, and other environmental substances.

The shapes and/or dimensions of the first side 302 a and the second side302 b are configured to impart comfort for user wearability. Forinstance, the second side 302 b includes an inner curved sectionconfigured to accommodate or conform to bulges in a user's legs, arms,or hip. The illustrated device housing 302 has a height of 2.5 inches, awidth of 2.5 inches and a depth or thickness of 0.75 inches. It shouldbe appreciated that the height, width, and/or depth of the kineticenergy harvesting device 102 may vary based on the size and/or number ofthe components 304 to 310, intended use (e.g., automotive, aerospace,personal, etc.), application, etc.

The example magnet housing 304 is configured to enclose forcetransducers for charging the battery 306. As described in more detailbelow in conjunction with FIG. 5, each of the magnet housings 304 a and304 b are configured to have a tubular-shape capped at each end byend-cap magnets. The magnet housings 304 a and 304 b also include atleast one wire coil (e.g., an inductor coil) and a central magnet. Thewire coils are positioned to be adjacent to ends of the central magnetso that the central magnet passes through or in proximity to the wirecoils when the central magnet oscillates between the end-cap magnetswithin the magnet housing 304. The poles of the end-cap magnets and thecentral magnet are configured to create a repulsion force to suspend thecentral magnet within the magnet housing 304. For instance, a south-poleof a first end-cap magnet is configured to face the south-pole of thecentral magnet and a north-pole of a second end-cap magnet is configuredto face the north-pole of the central magnet.

Also, as disclosed in more detail below, the end-cap magnets may bereplaced and/or supplemented to change the repulsion magnetic force withthe central magnet, thereby changing a movement speed and oscillation ofthe central magnet. Further, in some embodiments, the wire coils may beadjusted based on the speed and oscillation of the central magnet sothat the strongest magnetic field points on the central magnet passthrough a center and/or a majority of the wire coils while moving thecentral magnet. Such configurations of the end-cap magnets and the wirecoils enables the kinetic energy harvesting device 102 to be optimizedfor a user's activity and/or personal characteristics (e.g., gender,height, weight, etc.).

The example magnet housing 304 may comprise ABS, nylon, a polycarbonate,etc. An interior surface of the magnet housing 304 may be smoothedand/or coated to reduce friction of the central magnet contacting theinner walls of the magnet housing 304 while moving. In one embodiment,the coating may include a graphite powder or film.

While FIG. 3 shows the magnet housings 304 a and 304 b, it should beappreciated that the kinetic energy harvesting device 102 may includefewer or additional magnet housings. For example, the kinetic energyharvesting device 102 may have as few as one magnet housing or as manyas 1,000 to 10,000 magnet housings (as shown in FIG. 19) based, forexample, on an application of the kinetic energy harvesting device 102,technology constraints, etc. For instance, the kinetic energy harvestingdevice 102 may be used in an automotive application to provide power toan automobile and include hundreds of magnet housings. Alternatively,the size of the magnet housing 304 may change based on application ortechnology. For example, larger magnet housings may be used toaccommodate larger central magnets or smaller magnet housings may beused to enclose micro or nano-sized magnets for microelectromechanicalsystems (“MEMS”)-based applications.

As mentioned above, the example battery 306 is configured to store 1,000mAh. In other examples, the battery 306 may be configured to store lessor additional charge. Further, while the single battery 306 is shown, itshould be appreciated that two or more batteries may be used. Multiplebatteries may be connected in series and/or parallel to distributecharge. The battery 306 may by of any chemistry including nickelcadmium, nickel metal hydride, lithium ion, etc. In some instances, thebattery 306 may be replaced and/or supplemented by a capacitor orinductor. The capacitor may include a super-capacitor, anultra-capacitor, or an electrolytic capacitor. The battery 306 mayinclude circuitry to monitor (or control) temperature, charge rate,discharge rate, and/or stored energy. For instance, the battery 306 mayinclude a current sensor and a switch configured to disconnect thebattery 306 if a charge rate or discharge rate exceeds a threshold.

The example circuitry 308 is configured to rectify an AC voltage fromthe inductive wire coils within the magnet housing 304 into a DC voltageused to charge the battery 306. As discussed in more detail inconjunction with FIG. 4, the example circuitry 308 may also include oneor more controllers to manage or control the charge/discharge of thebattery 306. A discharge controller may also transform voltage/currentfrom the battery 306 into an electrical signal for transmission via thewired connection 204 (and corresponding interfaces) to the portableelectronic device 202. The circuitry 308 may further include a processorconfigured to monitor or determine a rate of charge/discharge and/or acharge level of the battery 306. The processor may be configured tocommunicate wirelessly the rate and/or charge level to a portableelectronic device of a user.

The example connection interface 310 is configured to connect orotherwise electrically couple the kinetic energy harvesting device 102with a portable electronic device. The illustrated connection interface310 includes a USB interface 310 a and a micro-USB interface 310 b. Inother embodiments, the connection interface 310 may include additionalor fewer interfaces, such as, for example, an Apple® Lightning™interface. In yet alternative embodiments, the connection interface 310may include a wireless interface (e.g., one or more inductors) totransmit the power wirelessly to a personal electronic device. In thesealternative embodiments, the connection interface 310 may be configuredto communicate with (or otherwise detect) a portable electronic deviceprior to wirelessly transmitting power from the battery 306.

FIG. 4 shows a diagram of the circuitry 308 of FIG. 3, according to anexample embodiment of the present disclosure. As discussed above, thecircuitry 308 within the kinetic energy harvesting device 102 iselectrically connected to the wire coils and the battery 306. Theillustrated circuitry 308 is only one example as to how an AC voltagefrom the wire coils is converted into a DC voltage, stored to thebattery 306, monitored, and discharged from the battery 306. Otherembodiments may include additional or fewer analog and/or digitalcomponents and/or surface mount components (e.g., resistors, capacitors,diodes, amplifiers, etc.).

The example circuitry 308 includes rectifiers 402 a and 402 b to convertan AC voltage or signal from inductive wire coils 404 and 406 of themagnet housing 304 into a DC voltage. Each of the magnet housings 304includes the two inductive wire coils 404 and 406. A first wire coil 404is positioned at a first end of a central magnet 408 in a restingposition and the second wire coil 406 is positioned at a second end ofthe central magnet 408. During movement of the central magnet 408,current is generated in the wire coils from electromagnetic couplingwith the central magnet. The current causes a voltage to form across thewire coils 404 and 406. As shown in FIGS. 6 and 7, a movement of thecentral magnet 408 toward the first wire coil 404 generates a positivevoltage across the first wire coil 404 and a negative voltage across thesecond wire coil 406. Likewise, movement of the central magnet 408toward the second wire coil 406 generates a negative voltage across thefirst wire coil 404 and a positive voltage across the second wire coil406. Summing the voltage outputs from the first and second wire coils404 and 406 would cancel the positive and negative voltages, therebygenerating zero net voltage. Accordingly, the first and second wirecoils 404 and 406 are rectified separately so that the positive andnegative voltages may separately be used to charge the battery 306.

As shown in FIG. 4, the rectifier 402 a is electrically coupled to thefirst wire coils 404 a and 404 b and the rectifier 402 b is electricallycoupled to the second wire coils 406 a and 406 b. Such a configurationassumes that the central magnets 408 a and 408 b are magneticallyaligned vertically or coupled to move in the same direction at the sametime. For instance, a north-pole of the central magnet 408 a may bealigned with a south-pole of the central magnet 408 b, thereby couplingthe magnets 408 and ensuring that the rectifiers 402 receive the samepositive or negative voltage from each of the magnet housings 304.

The voltages from the wire coils 404 a and 404 b may be connected inseries and summed prior to being rectified by the rectifier 402 a.Alternatively, the voltage from the wire coils 404 a and 404 b may beseparately rectified by rectifiers connected in series. The resultingrectified DC voltages are summed or otherwise combined. Likewisevoltages from the wire coils 406 a and 406 b may be connected in seriesand summed prior to be rectified by the rectifier 402 b or separately byrespective rectifiers. In yet alternative embodiments, a voltageinventor may be connected to one of the first wire coil 404 a or thesecond wire coil 406 a to enable voltages from the wire coils 404 a and406 a (and 404 b and 406 b) to be summed without cancellation.

After rectification, a battery charge controller 410 is configured tostore the DC voltage to the battery 306. The battery charge controller410 may include a current sensor, a voltage detector, a temperaturesensor, one or more switches, and/or one or more inverters. The currentsensor is configured to determine a current flowing into (or out of) thebattery 306 and may include one or more current mirrors. The voltagesensor is configured to detect a voltage being applied to the battery306 for charging and/or detect a current charge level of the battery306. The voltage sensor may also be configured to detect voltage levelswithin individual cells of the battery 306 to enable the controller 410to control uniform charging among the cells. The temperature sensor isconfigured to monitor a temperature of the battery 306. The switches(e.g., mechanical switches or transistors) are configured toconnect/disconnect the battery 306 from charging. The inverters may beused to convert a negative DC voltage into a positive voltage forcharging the battery. The sensors, switches, and/or inventors may beimplemented with passive components, active digital/analog components ora combination thereof.

The current, voltage, and temperature sensors may be used to enable thecontroller 410 to monitor the rate at which the battery 306 is chargedto prevent damage from overcurrent conditions. The battery chargecontroller 410 may also use the sensors to limit the charge rate whenthe battery 306 is close to capacity and prevent additional charge frombeing added when the battery 306 is full. The controller 410 may causeswitches to actuate to disconnect the battery 306 from being charged.During operation, the controller 410 receives a positive DC voltage fromone of the rectifiers 402 and a negative DC voltage from the other ofthe rectifiers 402. The controller 410 is configured to charge thebattery 306 with the positive DC voltage while converting or invertingthe negative DC voltage. The controller 410 then charges the battery 306with the inverted positive DC voltage. In some instances, the negativeDC voltage may be inverted and combined with the positive DC voltageprior to being used to charge the battery 306. In other instances, thecontroller 410 may be configured to filter or disregard the negative DCvoltage.

The example discharge controller 412 is configured to discharge currentand/or voltage from the battery 306 to charge a portable electronicdevice 202. The discharge controller includes a current sensor, avoltage detector, a temperature sensor, one or more switches, and/or oneor more voltage regulators/converters. The current, voltage, andtemperature sensors and switches are configured to perform the sameoperations as described in conjunction with the battery chargecontroller 410. For example, the current sensor is configured to measurea discharge current from the battery 306. In some embodiments thedischarge controller 412 may be included within and/or the samecomponent as the battery charge controller 410.

The example voltage regulator/converter of the discharge controller 412is configured to convert the current and/or voltage from the battery 306into one or more electrical signals for transmission via the wiredconnection 204. The discharge controller 412 may include logic orcomputer readable instructions that specify what voltage is to be outputbased, for example, on which interface is being used or a type ofportable electronic device 202. For instance, the discharge controller412, after sensing a connection of the portable electronic device 202 toa USB interface of the connection interface 310, converts currentdischarged from the battery 306 into a voltage signal compatible withUSB standards.

The discharge controller 412 may also be configured to disconnect thebattery 306 from discharging current when a portable electronic device202 is not present (or connected) and/or when the remaining charge onthe battery 306 reaches a specified threshold (e.g., 10%). In instanceswhere the discharge controller 412 prematurely ends the charging of theportable electronic device 202 due to low charge levels on the battery306, the discharge controller 412 may be configured to transmit amessage to the portable electronic device 202 indicating that charginghas stopped. The portable electronic device 202 may display the contentsof the message to a user.

The example circuitry 308 of FIG. 4 may also into a processor 414configured to communicate information about the kinetic energyharvesting device 102. The processor 414 may communicate with theportable electronic device 202 via the connection interface 310 inconjunction with the discharger controller 412 charging the device 202.Additionally or alternatively, the kinetic energy harvesting device 102may be configured to communicate with another portable electronic device416 that is not being charged. For instance, the processor 414 may becommunicatively coupled to (or include) a transceiver 418 that enableswireless communication (e.g., NFC, RFID, Bluetooth®, Wi-Fi, etc.) withthe other portable electronic device 416.

The example processor 414 is configured to communicate with the batterycharge controller 410 and/or the discharge controller 412 to receive orotherwise determine a charge/discharge rate of the battery 306, a chargelevel of the battery 306, one or more detected fault conditions of thebattery 306, one or more detected fault conditions associated with themagnet housing 304, etc. For example, the processor 414 and/or thecharge controller 410 may determine that one of the magnet housings 304is experiencing an issue when voltage is received from, for example, thehousing 304 a but is not received (or less voltage is received) from thehousing 304 b.

The processor 414 is configured to transmit the battery charge/dischargerate information, the charge available information, and faultinformation to one of the devices 416 and 202. In some embodiments, theprocessor 414 may include one or more algorithms or machine readableinstructions to determine the charge/discharge rate based on currentsensor measurements provided by the controllers 410 and 412. Theprocessor 414 may also include one or more algorithms or instructions todetermine an activity of a user or calories burned performing anactivity.

In some embodiments, the processor 414 may include one or morealgorithms configured to determine an amount of time for a user toperform an activity (based on detected charging rates of the battery306) to reach a specified or threshold battery charge level. Forexample, the processor 414 may detect that a user is walking andtransmit a message to the device 416 indicating that walking 10,000steps would generate enough power to charge the device 416 for 3 hoursor another smaller device such as a smartwatch or fitness tracker (e.g.,the device 202) 24 or 72 hours. The processor 414 may also send one ormore messages that indicate a different duration if the user performs adifferent activity (e.g., 1 hour of cycling, 30 minutes of running, or 5minutes of having sex instead of taking 10,000 steps to achieve the samecharge).

It should be appreciated that at least some of the components 302 to310, 402 to 414, and 418 of FIGS. 3 and 4 may be included within theportable electronic device 202. For example, the portable electronicdevice 202 may be a smartphone that includes (or is otherwise integratedwith) one or more magnet housings 304 and the circuitry 308. The batteryof the smartphone may be charged by the magnet housing 304 inconjunction with the circuitry 308. Such a configuration enables theportable electronic device 202 to self-charge without a user having toseparately carry the device housing 302.

In some embodiments, the smartphone may include two batteries. A firstbattery is configured to provide power to the smartphone and a secondbattery is configured to store charge from the magnet housings. Thesecond battery, in conjunction with circuitry and/or logic is configuredto charge the first battery when specified conditions are reached (e.g.,a charge level of the first battery dropping to a specified threshold, acharge level of the second battery reaching a specified threshold,reception of an instruction from a user via a mechanical button or viaan interface of the smartphone, when the smartphone is powered off, whenthe smartphone is in a sleep or non-use state, etc.). In some instances,the portable electronic device 202 may also be configured to chargeother devices using the first and/or second battery.

Example Magnet Housing

FIG. 5 shows a diagram of the example magnet housing 304 of FIGS. 3 and4, according to an example embodiment of the present disclosure. Theexample magnet housing 304 is illustrated as having a tubular-shape witha height of about 2.5 inches and a diameter of 0.5 inches. The magnethousing 304 includes an inner surface (i.e., the inside of the tube) andan outer surface (i.e., the outside of the tube). It should beappreciated that the size and/or shape of the magnet housing may vary.For example, the magnet housing 304 may have a rectangular or blockshape, a height anywhere between 0.1 to 200 inches, and/or a diameteranywhere between 0.1 to 50 inches. The size of the magnet 408 and thewire coils 404 and 406 may vary proportionally based on the dimensionsof the magnet housing 304.

The example magnet housing 304 includes the wire coils 404 and 406, thecentral magnet 408, and end-cap magnets 502 and 504. The wire coils 404and 406 are separated by a space 506 of the magnet housing 304. The wirecoils 404 and 406 are configured to have heights similar to the heightof the magnet 408 and are positioned such that, at rest, the top of thecentral magnet 408 is centered within a middle 508 of the wire coil 404and the bottom of the central magnet 408 is centered within a middle 510of the wire coil 406. The wire coils 404 and 406 may include any metalsuch as copper or gold and may or may not be insulated. In someinstances, the wire coils 404 and 406 are wound around an outsidesurface of the magnet housing 304. In these instances, the magnethousing 304 may be covered by a plastic or film. In other instances, thewire coils 404 and 406 may be wound on an inner surface (or integratedinside) of the magnet housing 304. In yet alternative examples, the wirecoils 404 and 406 may integrated with a separate piece of plastic thatmay be placed inside of the magnet housing 304 or around the outside ofthe magnet housing 304.

While the disclosure herein references the wire coils 404 and 406, itshould be appreciated that other types of magnetic inductors may beused. For example, a solenoid or an inductor with a core may instead beused. In these examples, the core may be metallic and/or magnetic.

Also, while the wire coils 404 and 406 are shown as having heightssimilar to the central magnet 408, it should be appreciated that theheights of the wire coils 404 and 406 may vary. For instance, theheights of the wire coils 404 and 406 may be less than the centralmagnet 408 (e.g., half the height) or greater than the central magnet408, such as the height shown in FIG. 4. Generally, the wire coil 404may be placed anywhere between a center 512 of the magnet housing 304and the end-cap magnet 502 and the wire coil 406 may be placed anywherebetween the center 512 of the magnet housing 304 and the end-cap magnet504, such as the placement shown in FIG. 4. Moreover, the wire coils 404and 406 may include wires of any thickness or diameter and/or thespacing between individual wires within the wire coils 404 and 406 mayrange from 0.1 mm to tens of centimeters.

It should be appreciated that the top and bottom of the central magnet408 has the strongest magnetic fields. The strongest current isaccordingly induced within the coils 404 and 406 (or voltage across thecoils 404 and 406) when the top or bottom of the central magnet 408passes adjacent to or in proximity of the coils 404 and 406. In thisconfiguration, even minimal perturbation of the central magnet 408induces a current within the coils 404 and 406. If, for example, theheights of the coils 404 and 406 were smaller such that the ends of thecentral magnet 408 extended past the coils 404 and 406 at rest or duringmovement, much of the magnetic field of the central magnet 408 would notpass through the coils 404 and 406, thereby inducing a relatively lowamount of current.

The example magnet housing 304 is connected to the end-cap magnets 502and 504. The end-cap magnet 502 is connected to (or otherwise integratedwith) a first end 514 of the magnet housing 304 and the end-cap magnet504 is connected to a second end 516 of the magnet housing 304. Theend-cap magnets 502 and 504 are configured to enclose the central magnet408 within an inside of the magnet housing 304. The end-cap magnets 502and 504 may be dimensioned to fit inside of the magnet housing 304.Alternatively, the end-cap magnets 502 and 504 may be configured toconnect around an outside at the ends of the magnet housing 304.

The end-cap magnets 502 and 504 are configured to suspend the centralmagnet 408 within the magnet housing 304. For instance, the south-poleof the end-cap magnet 502 is configured to face the south-pole of thecentral magnet 408 while the north-pole of the end-cap magnet 504 isconfigured to face the north-pole of the central magnet 408. Themagnetic field strengths of the end-cap magnets 502 and 504 issufficient to oppose the similarly poled-sides of the central magnet408, thereby causing the central magnet 408 to be suspended within themagnet housing 304. In some embodiments, the end-cap magnets 502 and 504and the central magnet 408 are configured to have the same magneticfield strength. For instance, the end-cap magnets 502 and 504 and thecentral magnet 408 may be N52 neodymium magnets. In other embodiments,the end-cap magnet 504, which is at a bottom of the magnet housing 304may be configured to have a greater field strength than the end-capmagnet 502 to overcome the downward gravitational pull on the centralmagnet 408.

FIGS. 6 and 7 show diagrams of current generation within the wire coils404 and 406 as the central magnet 408 oscillates, according to anexample embodiment of the present disclosure. During movement of a user,the central magnet 408, suspended within the magnet housing 304oscillates vertically. FIG. 6 shows a diagram of the central magnet 408moving upward and FIG. 7 shows a diagram of the central magnet 408moving downward. As the central magnet 408 moves, a magnetic flux isgenerated around the wire coils 404 and 406. The flux experienced by thewire coil 404 is opposite in polarity from the flux experienced by thewire coil 406. The magnetic flux causes the wire coils 404 and 406,operating as inductors, to induce a current to flow and a voltage toform across each of the coils. The voltage across the wire coil 404 isopposite in polarity compared to the voltage across the wire coil 406.The wire coils 404 and 406 are accordingly wired to the rectifiers 402appropriately such that the voltages are added rather than subtracted.In some instances, a voltage inverter may be electrically coupled to oneof the wire coils 404 and 406 to enable the downstream voltages to besummed in series prior to being transmitted to the rectifier 402.

FIGS. 8 and 9 show diagrams of example graphs 800 and 900 that show avoltage measured across the wire coil 404 during a period of time,according to an example embodiment of the present disclosure. The graph800 of FIG. 8 shows voltage across the wire coil 404 while a user isrunning and the graph 900 of FIG. 9 shows voltage across the same wirecoil 404 while a user is walking. The voltage is positive as the centralmagnet 408 moves to the end-cap magnet 502 and is negative as thecentral magnet 408 moves toward the end-cap magnet 504. The amplitude ofthe voltage in the graph 900 is generally lower than the amplitude ofthe voltage in the graph 800 because the central magnet 408 oscillatesat a slower speed (and/or moves less in each direction) when the user iswalking compared to running. As discussed above, the rectifier 402 isconfigured to convert the AC voltage shown in the graphs 800 and 900into a DC voltage for charging the battery 306. It should be appreciatedthat the wire coil 406 generates the same voltages as shown in thegraphs 800 and 900 but at an opposite polarity.

FIG. 10 shows a diagram of the magnet housings 304 a and 304 b withinthe kinetic energy harvesting device 102, according to an exampleembodiment of the present disclosure. As mentioned above, the magnethousing 304 b is orientated such that the poles of the magnets 408 b,502 b, and 504 b are opposite in polarity than the poles of the magnets408 a, 502 a, and 504 a. Such a configuration facilitates magneticcoupling between the central magnets 408 a and 408 b so that they areattracted to each other and accordingly move/oscillate at the same timeand in the same direction. This magnetic coupling may increase theamount of voltage generated since more magnetic force is applied to eachof the coils 404 and 406. As discussed above, the wire coils 404 a and404 b are connected in series and the wire coils 406 a and 406 b areseparately connected in series to sum the similarly poled-voltages.

It should be appreciated that reversing the polarity of the centralmagnet 408 b to match the polarity of the central magnet 408 a in thevertical orientation causes the central magnets 408 to repel each other.This repelling force dampens oscillation speed. The repelling force alsomakes it very difficult to position both of the central magnets 408 at acenter of the respective magnet housing 304 in a rest position.

Magnet Housing Embodiments

FIGS. 11 to 14 show diagrams of different configurations of the magnethousing 304 of FIGS. 3 to 10, according to example embodiments of thepresent disclosure. As mentioned above, the magnet housing 304 may beadjustable to change a speed and/or oscillation characteristic of thecentral magnet 408. The adjustments are made to the magnet housing 304to optimize the speed or oscillation of the central magnet 304 based ona motion of a user. The adjustments may be made by a user based on, forexample, an activity level or activity to be performed by the user. Theadjustments may also be made by a user based on physical attributes orcharacteristics of the user. Additionally or alternatively, theadjustments may be made by a manufacturer of the kinetic energyharvesting device 102. For instance, a manufacturer may make a model ofthe device 102 optimized for high intensity activities (e.g., running,soccer, etc.), a model of the device 102 optimized for moderateintensity activities (e.g., speed walking, swimming, cycling, etc.),and/or a model of the device 102 optimized for low intensity activities(e.g., causal walking, sitting, sleeping, etc.).

FIG. 11 shows a diagram of the unmodified magnet housing 304 of FIG. 5for reference. FIGS. 12 to 14 show modifications that may be made to themagnet housing 304. In particular, FIG. 12 shows an adjustment thatincludes moving the end-cap magnets 502 and 504 toward a center of themagnet housing 304. The end-cap magnets 502 and 504 may be moved by auser sliding a lever or actuating a button on the magnet housing 304and/or on an exterior of the device housing 302. The end-cap magnets 502and 504 may also be moved by a user physically pushing the magnets 502and 504. Moving the end-cap magnets 502 and 504 closer to the center ofthe magnet housing 304 accounts for lower movement of the central magnet408 corresponding to lower intensity activities. Alternatively, in someinstances, the end-cap magnets 502 and 504 may be moved closer to thecenter of the magnet housing to dampen the speed and/or oscillation ofthe central magnet 408, which may be preferable for higher intensityactivities where the central magnet 408 receives more kinetic energy.

FIG. 13 shows an adjustment that includes moving the end-cap magnets 502and 504 away from a center of the magnet housing 304. A user may movethe end-cap magnets 502 and 504 away from central magnet 408 by, forexample, sliding a lever causing the height of the magnet housing 304 toexpand (e.g., the magnet housing 304 may include a telescopingcomponent). Alternatively, a user may connect different end-cap magnetsthat include tubing material connectable to the ends of the magnethousing 304, thereby extending the height of the magnet housing 304. Amanufacturer may simply use a magnet housing 304 with a greater height.Moving the end-cap magnets 502 and 504 away from the center of themagnet housing 304 accounts for higher movement of the central magnet408 corresponding to higher intensity activities. Alternatively, in someinstances, the end-cap magnets 502 and 504 may be moved further from thecenter of the magnet housing to reduce a dampening force affecting thespeed and/or oscillation of the central magnet 408, which may bepreferable for lower intensity activities where the central magnet 408receives less kinetic energy.

FIG. 14 shows an adjustment to the example discussed in conjunction withFIG. 13 that includes moving the wire coils 404 and 406. The wire coils404 and 406 may be moved by a user, for example, sliding a lever.Alternatively, the wire coils 404 and 406 may be directly moved by auser. The wire coils 404 and 406 are adjustable to account for less orgreater movement of the central magnet 408. As discussed, greatercurrent is generated when the ends of the magnet 408 pass through or inproximity to the wire coils 404 and 406. Moving the wire coils 404 and406 along a height of the magnet housing 304 helps ensure that themagnet 408 is within the wire coils 404 and 406 for a majority of themovement.

In addition to being moved, the example wire coils 404 and 406 areexpanded in height to cover virtually all movement of the central magnet408 for relatively intense activities where more movement is expected.In examples where the central magnet 408 is expected to have lessmovement, the wire coils 404 and 406 may be moved closer to a center ofthe magnet housing 304. Further, the wire coils 404 and 406 may becondensed together so the same amount of wire coils are traversed by thecentral magnet 408 with relatively less movement. Theexpansion/contraction of the wire coil height may be adjustable by auser via one or more levers accessible through the magnet housing 304and/or the device housing 302. Alternatively, a user may directly expandor contract the wire coils 404 and 406. In yet alternative embodiments,a user (or a manufacturer) may add or remove wire coils to the magnethousing 304.

Magnet Embodiments

FIGS. 15 to 18 show diagrams of different configurations of the end-capmagnets 502 and 504 and the central magnet 408 of FIGS. 3 to 10,according to example embodiments of the present disclosure. The end-capmagnets 502 and 504 and/or the magnet housing 304 may be adjustable tochange a speed and/or oscillation characteristic of the central magnet408. The adjustments are made to optimize the speed or oscillation ofthe central magnet 304 based on a motion of a user. The adjustments maybe made by a user based on, for example, an activity level or activityto be performed by the user. The adjustments may also be made by a userbased on physical attributes or characteristics of the user.Additionally or alternatively, the adjustments may be made by amanufacturer of the kinetic energy harvesting device 102. For instance,a manufacturer may change the end-cap magnets 502 and 504 based on arated intensity level of the device 102.

FIG. 15 shows a diagram of the unmodified magnet housing 304 and end-capmagnets 502 and 504 of FIG. 5 for reference. FIGS. 16 and 17 showdiagrams of modifications that may be made to the end-cap magnets 502and 504. In particular, FIG. 16 shows that a user (or manufacturer) mayreplace the end-cap magnets 502 and 504 with end-cap magnets 1602 and1604 that have a different size and/or magnetic field strength. The useof the stronger end-cap magnets 1602 and 1604 may constrain the centralmagnet 408 for relatively high or low intensity activities. The end-capmagnets 502 and 504 are replaced by removing or disconnecting themagnets 502 and 504 from the magnet housing 304 and connecting themagnets 1602 and 1604. It should be appreciated that the wire coils 404and 406 may be reduced in height to match the constrained movement ofthe central magnet 408, as discussed in conjunction with FIG. 14.

FIG. 17 shows a diagram where second end-cap magnets 1702 and 1704 areadded to already connected end-cap magnets 502 and 504. The addition ofthe second end-cap magnets 1702 and 1704 increases the magnetic fieldstrength, similar to adding the stronger end-cap magnets 1602 and 1604in FIG. 16. The second end-cap magnets 1702 and 1704 may be magneticallyand/or mechanically coupled to the respective magnets 1502 and 1504.Alternatively, the end-cap magnets 1702 and 1704 may be connected to anexterior of the device housing 302 while still being aligned with theend-cap magnets 502 and 504 to enable a user to easily configure thekinetic energy harvesting device 102. For instance, the device housing302 may include one or more slots or recessed portions to accommodateand secure the end-cap magnets 1702 and 1704. The slots or recessedportions are aligned with the internally located end-cap magnets 502 and504, thereby increasing the magnetic field strength. It should also beappreciated that the addition of some end-cap magnets may reduce themagnetic field strength.

In some embodiments, the strength of the end-cap magnets 502 and 504 maybe adjusted electronically rather than physically. For instance, theend-cap magnets 502 and 504 may be connected to an electrical circuitconfigured to control the magnetic strength of the magnets 502 and 504.A user may select a button on the outside of the device housing 102 orelectronically via the devices 202 or 416, which causes the electricalcircuit to accordingly increase or decrease the magnetic field strengthof the end-cap magnets 502 and 504. The button or electronic setting mayinclude, for example, an activity level or desired activity type to beperformed by the user, which causes, for example, the processor 414 ofFIG. 4 to determine an appropriate magnetic field strength andaccordingly tune or set the magnetic field strength of end-cap magnets502 and 504.

FIG. 18 shows a diagram of the example magnet housing 304 including twocentral magnets 1802 and 1804 that are aligned with respective wirecoils 1806, 1808, 1810, and 1812. The wire coils 1806 and 1810 may beconnected in series and the wire coils 1808 and 1812 may separately beconnected in series. The central magnets 1802 and 1804 are aligned sothat they operate as an end-cap of each other. For instance, theoppositely facing ends of the central magnets 1802 and 1804 have thesame polarity to ensure the magnets 1802 and 1804 remain separated by apredetermined distance while still being able to move or oscillate inthe same direction at the same speed. The damping caused by the use ofthe two central magnets 1802 and 1804 is offset by the increased energyoutput of the additional magnet and wire coils.

It should be appreciated that the dimensions of the central magnet 408may change based on application, technology, etc. For example, thecentral magnet 408 may have a height, width, and/or thickness withnano-dimensions or micro-dimensions. Alternatively, the central magnet408 may have a height, width, or thickness that ranges from a fewcentimeters or inches to hundreds of inches. FIG. 19 shows a diagramwhere an array of relatively small central magnets is used within adevice housing and/or one or more magnet housings, according to exampleembodiments of the present disclosure. The kinetic energy harvestingdevice 102 may accommodate an array of the magnet housings 304 toincrease an amount of kinetic energy captured. The central magnets maybe positioned and/or spaced to facilitate magnetic coupling so that theymove at the same speed in the same direction. The array of magnethousings may charge one or more batteries. For example a top portion ofthe array may charge a first battery and a bottom portion of the arraymay charge a second battery that is electrically parallel to the firstbattery.

CONCLUSION

It should be appreciated that all of the disclosed methods andprocedures described herein can be implemented using one or morecomputer programs or components. These components may be provided as aseries of computer instructions on any computer-readable medium,including RAM, ROM, flash memory, magnetic or optical disks, opticalmemory, or other storage media. The instructions may be configured to beexecuted by a processor, which when executing the series of computerinstructions performs or facilitates the performance of all or part ofthe disclosed methods and procedures.

It should be understood that various changes and modifications to theexample embodiments described herein will be apparent to those skilledin the art. Such changes and modifications can be made without departingfrom the spirit and scope of the present subject matter and withoutdiminishing its intended advantages. It is therefore intended that suchchanges and modifications be covered by the appended claims.

The invention is claimed as follows:
 1. A kinetic energy harvestingapparatus comprising: a first magnet housing and a second magnet housingeach configured to have a tubular shape and include: a first end-capmagnet configured to connect to a first end of the magnet housing; asecond end-cap magnet configured to connect to a second end of themagnet housing; a first wire coil configured to be connected to themagnet housing between the first end and a center of the magnet housing;a second wire coil configured to be connected to the magnet housingbetween the second end and the center of the magnet housing; and acentral magnet configured to be located within the magnet housingbetween the first end and the second end such that a north-pole end ofthe central magnet faces a north-pole of the first end-cap magnet and asouth-pole end of the central magnet faces a south-pole of the secondend-cap magnet causing the central magnet to be suspended between thefirst and second end-caps of the magnet housing, wherein the first wirecoil has a first height along the respective magnet housing and includesa first center, with respect to the first height along the respectivemagnet housing, that is positioned adjacent to the north-pole end of thecentral magnet when the central magnet is at rest, wherein the secondwire coil has a second height along the respective magnet housing andincludes a second center, with respect to the second height along therespective magnet housing, that is positioned adjacent to the south-poleend of the central magnet when the central magnet is at rest, andwherein the central magnets of the first and second magnet housings arepositioned such that the north-pole of the central magnet of the firstmagnet housing is vertically aligned in parallel with the south-pole ofthe central magnet of the second magnet housing when the central magnetsare at rest or are moving through the respective magnet housings.
 2. Theapparatus of claim 1, wherein the first wire coil and the second wirecoil are configured to be internal to the magnet housing and includeinsulated wire.
 3. The apparatus of claim 1, wherein a combination ofthe first height and the position of the first wire coil is configuredto enable the first end of the central magnet to pass through the firstwire coil while concurrently enabling the second end of the centralmagnet to pass through the second wire coil.
 4. The apparatus of claim1, wherein the second end-cap magnet has a greater magnetic fieldstrength than the first end-cap magnet to compensate for Earth'sgravity.
 5. The apparatus of claim 1, wherein the first and the secondend-cap magnets and the central magnet each include a N52 Neodymiummagnet.
 6. The apparatus of claim 1, wherein the first and secondend-cap magnets have less field strength than the central magnet.
 7. Theapparatus of claim 1, wherein the magnet housing has a height between0.25 and 6 inches.
 8. The apparatus of claim 1, wherein the first heightand the second height along the respective magnet housing are eachsubstantially equal to a height of the respective central magnet.
 9. Akinetic energy harvesting apparatus comprising: first and secondtubular-shaped magnet housings that each include: a first end-cap magnetconfigured to connect to a first end of the magnet housing; a secondend-cap magnet configured to connect to a second end of the magnethousing; a first wire coil configured to be connected to the magnethousing between the first end and a center of the magnet housing; asecond wire coil configured to be connected to the magnet housingbetween the second end and the center of the magnet housing; and acentral magnet configured to be suspended within the magnet housingbetween the first end and the second end such that a north-pole end ofthe central magnet faces a north-pole of the first end-cap magnet and asouth-pole end of the central magnet faces a south-pole of the secondend-cap magnet, wherein the central magnets of the first and secondtubular-shaped magnet housings are positioned such that the north-poleof the central magnet of the first tubular-shaped magnet housing isvertically aligned in parallel with the south-pole of the central magnetof the second tubular-shaped magnet housing when the central magnets areat rest or are moving through the respective tubular-shaped magnethousings.
 10. The apparatus of claim 9, wherein at least one of thefirst end-cap magnet and the second-end cap magnet is detachable fromthe magnet housing.
 11. The apparatus of claim 10, wherein a third-endcap magnet may replace at least one of the detachable first-end capmagnet and the detachable second-end cap magnet, the third-end capmagnet having a different field strength than the first-end cap magnetand the second end-cap magnet.
 12. The apparatus of claim 11, whereinthe third-end cap magnet is used to replace at least one of thefirst-end cap magnet and the second-end cap magnet to change a speed andoscillation of the central magnet to correspond to a user's activity.13. The apparatus of claim 11, wherein the third-end cap magnet is usedto replace at least one of the first-end cap magnet and the second-endcap magnet to change a speed and oscillation of the central magnet tocorrespond to a user's physical attributes.
 14. The apparatus of claim9, wherein a third-end cap magnet may be connected to at least one ofthe first-end cap magnet and the second-end cap magnet to change a speedor an oscillation of the central magnet.
 15. The apparatus of claim 9,wherein a location of at least one of the first wire coil and the secondwire coil is adjustable along the magnet housing.
 16. The apparatus ofclaim 9, wherein the first wire coil has a height along the respectivemagnet housing and includes a first center, with respect to the heightalong the respective magnet housing, that is positioned adjacent to thenorth-pole end of the respective central magnet when the central magnetis at rest.
 17. A kinetic energy harvesting apparatus comprising: afirst tubular magnet housing including: a first end-cap magnetconfigured to connect to a first end of the magnet housing, a secondend-cap magnet configured to connect to a second end of the magnethousing, a first wire coil configured to be connected to the magnethousing between the first end and a center of the magnet housing, asecond wire coil configured to be connected to the magnet housingbetween the second end and the center of the magnet housing, and acentral magnet configured to be located within the magnet housingbetween the first end and the second end such that a north-pole of thecentral magnet faces a north-pole of the first end-cap magnet and asouth-pole of the central magnet faces a south-pole of the secondend-cap magnet causing the central magnet to be suspended between thefirst and second end-caps of the magnet housing; a second tubular magnethousing including: a first end-cap magnet configured to connect to afirst end of the magnet housing, a second end-cap magnet configured toconnect to a second end of the magnet housing, a first wire coilconfigured to be connected to the magnet housing between the first endand a center of the magnet housing, a second wire coil configured to beconnected to the magnet housing between the second end and the center ofthe magnet housing, and a central magnet configured to be located withinthe magnet housing between the first end and the second end such that anorth-pole of the central magnet faces the north-pole of a first end-capmagnet and a south-pole of the central magnet faces a south-pole of thesecond end-cap magnet causing the central magnet to be suspended betweenthe first and second end-caps of the magnet housing; a battery; and acircuitry configured to: rectify an AC voltage generated by the firstand second wire coils of the first and second tubular magnet housingsinto a DC voltage, and charge the battery using the DC voltage, whereinthe central magnets of the first and second tubular magnet housings arepositioned such that the north-pole of the central magnet of the firsttubular magnet housing is vertically aligned in parallel with thesouth-pole of the central magnet of the second tubular magnet housingwhen the central magnets are at rest or are moving through therespective tubular magnet housings.
 18. The apparatus of claim 17,further comprising a device housing configured to enclose the firsttubular magnet housing, the second tubular magnet housing, the battery,and the circuitry.
 19. The apparatus of claim 17, wherein the first wirecoils of the first tubular magnet housing and the second tubular magnethousing are configured to be wired in series and the second wire coilsof the first tubular magnet housing and the second tubular magnethousing are configured to be separately wired in series.
 20. Theapparatus of claim 17, wherein the central magnets of the first andsecond tubular magnet housings are configured to each have a heightalong the respective tubular magnet housings that is substantially equalto a height of the respective first wire coils.
 21. The apparatus ofclaim 17, wherein the central magnets of the first and second tubularmagnet housings are configured to be magnetically coupled to move in thesame direction at the same time to increase the amount of voltage summedby the circuitry.
 22. The apparatus of claim 17, wherein the circuitryis configured to: detect an electrical connection to a device; andcharge the device using the battery.
 23. The apparatus of claim 17,wherein the circuitry is configured to: determine a current charge ofthe battery; determine a rate at which the battery is being charged; andtransmit the current charge state and the rate to a user device.
 24. Theapparatus of claim 17, wherein the kinetic energy harvesting apparatusis included within a portable electronic device.
 25. The apparatus ofclaim 16, wherein the height of the first wire coil is substantiallyequal to a height of the central magnet.